ABSTRACT

The extent to which imagery and perceptual processes overlap in the brain has been the focus of a number of studies using different experimental methodologies. Here the authors report the results of a number of different experimental investigations exploring visual memory in a patient with a severe perceptual deficit (HJA). They demonstrate that HJA can perform imagery tasks well that require judgements about a single object or object part, however, he experiences difficulty on tasks where he has to respond to the spatial relations between the local parts of objects. He experiences similar difficulties in perceptual processing. The authors argue that the bottom-up coding of visual images is influenced by the same intermediate visual processes that serve object recognition. They assesses whether the perceptual deficit in agnosia impacts on short-term visual memory. Thus, with tests assessing knowledge of living things HJA performed at ceiling on the Animal Ears Test, Animal Size Test and in a Perceptual Differences Test.